Mutant protein offers promise of skin disease cure

Researchers from Loyola University Chicago said they have developed a mutant form of a protein that seems to cure mice of vitiligo, a skin condition found in millions of people around the world.

Vitiligo causes irregular, white patches of skin, which are most often found on areas of the body that are exposed to the sun, including the face, lips, arms, hands and feet. The skin disorder affects as many as 65 million people worldwide, with at least 1 million of them in the United States, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

The protein developed by Loyola University scientists changed mouse fur from salt-and-pepper-colored to its original black. The study announcing the finding was published Feb. 27 in the journal Science Translational Medicine.

"We're very excited about the results. We've been working toward this for many years, and it's great to have identified a way to possibly stop the development of the vitiligo," said I. Caroline Le Poole, professor in the pathology, microbiology and immunology departments at Loyola University Chicago Stritch School of Medicine and senior author of the paper.

The research was largely completed in the laboratories of Le Poole and her Loyola colleague Jose Guevara-Patino, with contributions from such institutions as Rush University Medical Center in Chicago.

The researchers developed an alternate form of the protein, HSP70i, which protects cells when they are under stressful conditions, Le Poole said.

"If that protein gets out of the cell, then it becomes kind of an alarm signal for the body. The immune system is alarmed and tries to figure out what to do about it, and attacks the immune cells. HSP70i seems to work like a switch in the development of vitiligo," she said. "If you can block it from coming in touch with the immune cells, you could then interfere with vitiligo development."

The researchers altered the protein by changing one amino acid, or building block. "We changed the molecule a little bit, so that it would no longer work. We used the switch to switch off the response of the immune cells," Le Poole said.

The researchers are "trying to show that vitiligo is an autoimmune disease, in which patients lose the source of pigmentation in the skin," Le Poole added. "Those (pigment) cells are attacked by your own immune system. We're trying to identify hereditary facts associated with the development of vitiligo."

The next step is to "make sure that this alternate form of HSP70i is safe for humans," Le Poole said. "We hope we can bring this to clinical trials in the future. We're certainly working on it."

The team has requested funding for a clinical trial, and Loyola University has applied for a patent for the protein.

Dr. David Norris, professor and chairman of the dermatology department at the University of Colorado at Denver, praised the study.

"It involves the very best techniques in the field," Norris said. "The study is well-controlled, a sophisticated project. The exciting part is that these DNA molecules may be able to be used on skin in humans, which would be a major therapeutic step forward, and which may be a prototype for other approaches that deliver DNA across the skin to inhibit autoimmune disease."